The invention relates to a support device with a bearing which is surrounded by a housing and which is provided with a first bearing part present inside the housing and with a second bearing part provided on a locking piece fastened to the housing so as to cooperate with said first bearing part, while the support device comprises an elastically deformable sealing element for preventing leakage of a fluid present between the two bearing parts along the locking piece.
The invention also relates to a data storage unit for accommodating an information disc, which unit is provided with a scanning unit for cooperating with the information disc and with a support device according to the invention for the rotary support of the information disc.
A support device of the kind mentioned in the opening paragraph is shown in FIG. 3 of British Patent 1 222 275. The known support device comprises a shaft which is rotatably supported in the housing by means of a radial dynamic groove bearing and an axial dynamic groove bearing. The first bearing part mentioned in the opening paragraph belongs to the axial groove bearing and comprises a bearing surface 13 which extends perpendicularly to the shaft, which is present on a flange 3, and which is provided with a pattern of grooves. The second bearing part also belongs to the axial groove bearing and comprises a bearing surface 14 which extends perpendicularly to the shaft, and which forms an inner wall of the locking piece with which the bearing space 5 present in the housing is closed off. A liquid lubricant is present between the bearing surfaces 13 and 14. To prevent leakage of the liquid lubricant along the locking piece, the known support device may be provided with a conventional sealing element which is known per se such as, for example, a sealing ring, which is not shown in the Patent and which is clamped in under pretension between the housing and the locking piece when the locking piece is provided on the housing. The known support device is further provided with grooves 12 against leakage of the liquid lubricant along the shaft 2.
A disadvantage of the use of such a sealing element in the known support device is that the positional accuracy of the locking piece relative to the housing is adversely affected by the pretension of the sealing element. The pretension of the sealing element may give rise to deformations of the fastening means by which the locking piece is fastened to the housing during or after fastening of the locking piece to the housing. Said deformations lead to small, undesirable displacements of the locking piece relative to the housing, whereby the position of the first bearing part relative to the second bearing part and the operation of the bearing are adversely affected.